Oil burner control



Jan. 1, 1935. G, R. TOWNSEND 1,985,031

OIL BURNER CONTROL Filed F'eb. 24, 1930 7g3 l 9 622 79 l Inventob:Geer/*ge R. Townsend,

His Attorneu Patented Jan. 1, 1935 PATEN y@FFICE incensi om BURNERooN'rnoL George R. Townsend, Schenectady, N. Y., assigner to GeneralElectric Company, a corporation of New York Application February 24,19st, serian No. 430,482

23 Claims.

My invention relates to control devices, and has for its principalobject a fully automatic control device for a burner for fluids.

Such an automatic oil burner is set forth in a copending application ofChester I. Hall, Serial No. 430,497, filed Feb. 24, 1930, and assignedto the same assignee as this application.

The present invention is an improvement of the device therein set forthand claimed, and of the device set forth and claimed in a copendingapplication of Harry R. Crago, Serial No. 430,- 480, filed Feb. 24,1930, and assigned to the same assignee.

The usual fluid fuel burner employs an electrically driven fuel supplymotor for furnishing fuel to the combustion chamber of the oil burnerfurnace. Some means for igniting the fuel is necessary and this isusually an electrical ignition system. A control mechanism is usuallyprovided for controlling operation of the fuel supply motor and ignitionsystems. A room thermostat responsive to room temperatures inturn-controls operation of the control mechanism to start and stop theburner in response to temperature variations.

The preferred embodiment of my invention consists of a synchronous motorfor continuously driving a time controlled mechanism which automaticallyswitches in the night or day thermostats which initiate operation of theapparatus. The time control mechanism does not form a part of thisapplication but is described and claimed in my copending application,Serial No. 399,835, filed Oct. 15, 1929, and assigned to the sameassignee.

The motor also drives what is termed a recycling mechanism. This deviceopens and closes the fuel supply motor circuit at short intervals. Itmay be used to open and close a valve or any ,w other device whichcontrols the fuel supply. The

purpose of such an operation is to present several opportunities forigniting the oil spray.

Although the ignition system for igniting the oil flame may becontinuously energized until flame is established, in my invention, therecycling mechanism causes the ignition system to be energized anddeenergized simultaneously with the fuel supply motor.

When the flame is established a heat responsive device placed in therebox of the furnace and operated by the name cuts out the ignitionsystem and locks in the fuel supply motor. This flame responsive devicemay also be placed in the stack.

Should the flame fail during operation, the heat responsive deviceenergzes the recycling mechanism to reignite the oil by reenergizing theignition system. A denite time period is provided after flame failurebefore the ignition and fuel supply motor circuits are reestablished bythe recycling device. This is accomplished by the setting of camscarried on a cam shaft, and forming part of the recycling mechanism.

In the present invention means are provided for permitting relativeadjustment of the cams whereby the time intervals in energization anddeenergization of the fuel supply motor` and ignition system may bevaried.

The recycling operation is accomplished by means of cam actuatedcontacts, which contacts are rendered operative whenever a starting coilis energized by the closing of a thermostat calling for heat. Thestarting coil operates a pivoted member upon which relatively adjustablecams are mounted, the pivoted member also carrying circuit closingcontacts. This brings the cam shaft into engagement with a drivingpinion of the synchronous motor. The rotation of the cams actuates thecontacts'to open and close the ignition system and fuel supply motorcircuits. In the event that the recycling device fails to cause ignitionof the fuel after a predetermined number of intermittent operations ofthe fuel supply motor and ignition system, a tripping means is providedfor rendering the control apparatus inoperative, thus invitinginspection to determine the cause of the failure of the apparatus tofunction.

My invention will be better understood from the following descriptionwhen considered in connection with the accompanying drawing, and itsscope will be pointed out in the appended claims.

The drawing shows a schematic diagram of the device with theimprovements thereon.

Referring to the drawing, furnace 60 has mounted adjacent thereto thefuel supply apparatus having a fuel supply motor 100, for directing fueltherein. Within the combustion chamber are mounted the ignitionelectrodes 103 and the thermostatic portion of the switch 104 which isresponsive to combustion conditions within the furnace. A safetypressure device 107 is mounted on top of the furnace.

The control mechanism includes a synchronous motor 61 which iscontinuously energized from the power supply lines L3 and L; by means ofconductors 91 and 61. A time control switch designated generally -at 62is driven through reduction gearing 110 by means of the synchronousmotor 61.

y attached to the back panel (not shown).

The pivoted members 621 and 622 are mounted on a shaft supported by thebrackets 119 and 120 These members are biased in a clockwise directionby means of the springs 123 and 122. The pivoted member 621 carriescontacts 111 and-112 electrically insulated from each other and pivotedmember 622 carries double contacts 113. The cams 114 and 115 with whichthe pivoted members have engagement operate the pivoted members so thatthe double contact 113 will be in contact with the lower contact 112 toplace thermostat 94 in the controlling circuit or in contact with theupper contact 111 to place the thermostat 93 in the controlling circuit.These circuits will be traced below. The driving shaft 160 upon whichthe cams 114 and 115 are rotatably mounted has xed thereto the dial 161.The cams are operably connected to the drive shaft 160 by mean-s of theadjusting members 117 and 118 which releasably engage the dial 161. Theadjusting members 117 and 118 are connected to the cams for the purposeof shifting the position of the cams on the shaft with respect to eachother to determine the time at which the contacts 113, 112, and 111 willbe shifted with respect to each other. A stop mem* ber 121 connected tothe back panel (not shown) and co-acting with the lug on the pivotedmember 622 limits the clockwise movement of the pivoted members when themembers are not in contact with the cams.

Therecycling mechanism includes a frame 68 pivotally supported inbrackets 132 and 133 attached to a back panel, not shown. This framecarries an armature 68 for rotating the frame clockwise whenever thepick-up or starting magnet 67 is energized. The arms 7l and 69' are alsocarried by the frame and rotate therewith. These arms rotatively supportthe cam shaft 124 upon which are mounted the driving gear 66 and therecycling cams 63 and 64. A spring 124' is for the purpose of returningthe cam shaft to its initial position whenever the frame drops back fromits operating position against the stop 67 attached to a back panel, notshown. Whenever the electromagnet 67 is energized it causes the armature68 to rotatethe frame in a. clockwise direction to mesh the driving gear66 with the gear 65 driven by the motor 61. This causes rotation of thecams 63 and 64 in a direction indicated by the arrow (on gear 66 tooperate the pivoted members 74 and 73 for controlling the motor andignition circuits in` a manner to be described later.. A stop 67referred to, limits the counter-clockwise movement of the frame when theframe is permitted to return to the inoperative position.

vCarried by frame 68 is a member 69 of insulating material which carriesa bridging member 69' carrying contacts. These contacts cooperate withthe contacts 135 and 136 on brackets which are attached to the backpanel, not shown, for completing the ignition circuit. to be describedbelow. Bracket and contact 136 are electrically connected to pivotedmember 74. The arm 71 carries a member 70 of insulating material whichcooperates with a member 711 for controlling a holding circuit to bedescribed.

The member 711 is pivotally mounted Ona bracket 125 attached to the backpanel, not

- shown.. To its lower end is attached by means of an insulating memberthe bridging member 126 which rcarries contacts cooperating with thecontacts 137 and 138 to complete a holding circuit to be describedbelow. Contacts 137 and 138 are supported by brackets 139 and 140attached to the back panel, not shown. When the frame 68 is rotated in aclockwise direction to mesh gears 65 and 66, the member 70 rotates themember 711 in a clockwise direction to close bridging member 126 oncontacts 137 and 138. When the electro-magnet 72 mounted upon the backpanel, not shown, is energized, it maintains the member 711 in theclosed position.

The pivoted switch members 73 and 74 carrying the contacts 75 and 76 aremounted in the brackets 128 and 127 vwhich are 'attached to the backpanel, not shown. Spring members 731 and 74" bias the switch members ina counterclockwise direction so that when the frame 68 is in itsinoperative position,v the lug 130 carried by pivoted member 73 contactswith the pin 130 which acts as a stop member and which is carried bybracket 128. The lug 1271 carried by the pivoted member 74 co-acts withthe stop member 127 carried by the bracket 127. The pivoted member 73has an ear 129 which pivotally supports a latch 73' which, when thepivoted member 73 is in its biased position against the pin 130,' ismaintained in a raised position, as shown, by means of the pin 130cooperating with the depending lug 129 on latch 73. When the pivotedmember 73 is rotated in a clockwise direction the lug 4129 on latch 73being moved out of engagement with the pin 130 drops behind the member711 to engage the same for a purpose to be described below.

When the frame 68 is rotated in a clockwise.

direction, the cams 63 and 64 contact with the curved upper ends ofpivoted members 74 and 73 and rotate them in a clockwise direction. Thedetailed operation of the cams and switch members will be describedbelow.

An overload tripping device includes a frame pivotally mounted in thebracket 801 attached to the back panel, not shown. A spring 80 biasesthe frame in a clockwise direction about its pivot. The frame haspivotally mounted thereon at 77 the latch member 77 which carries thelug 79. This lug is provided with a recess 792 into which the catch 79ts and normally holds the frame 80, as shown, against its bias. Thecatch is rigidly supported by the back panel, not shown. Mounted on theother end of the frame 80 and insulated therefrom is the bridging member81 carrying contacts which cooperate with the contacts 141 and 143 tocomplete a circuit, to be described later. The contacts 141 and 143 aresupported by the brackets 142 and 139 attached to the back panel, notshown.

Carried by the gear 66 is a pin 78 which cooperates with the latch 77 torotate the same in a clockwise direction about its pivot 77 to releasethe lug 79 from the catch 79. This permits the biasing spring 80 torotate the frame 80 about its pivot in a clockwise direction and move-the bridging member 81 to an open position out of contact with thecontacts 141 and 143. This opens a circuit to be described below.

The period of time necessary for the recycling .device to cycle out,that is for the mechanism to actuate the fuel supply motor and ignitionsystem a predetermined number of times and then be tripped out ofoperation is constant. The period of time during which the fuel supplymotor and ignition system remain energized and deenergized may be variedhowever.

This is accomplished by means of the cams 63 and 64. It will be seenthat cam 63 carries thereon a collar 631 provided with teeth. Cam 64carries the collar 641 having a single tooth engaging with teeth on cam63. By rotating cam 64 with respect to 63 in a counter-clockwisedirection, and engaging different teeth on cam 63, the cam surfaces willbe shifted with respect to each other due to the fact that the teeth on63 are of different spacing than the notches on the face of the cam 64.This affects the time of opening and closing of the contacts 75 and 76in the fuel supply. motor and ignition circuits since the pivotedmembers 74 and 73 are actuated according to the position of thecamsurfaces.

The fuel supply motor is connected to one side of the vline La by meansof conductor 101. The other side of the motor is connected to therecycling device through conductor 102. The ignition terminals 103 areconnected to the ignition transformer 91 by means of conductors 149 and150. A thermostatically operated switch mechanism 104 responsive to heatconditions in the furnace is placed in the rebox of the furnace 60 andis provided with two contacts/for completing circuits described belowthrough conductor or 106. This switch is described and claimed in mycopending application No. 417,923, led Jan. 2, 1930, and assigned to thesame assignee. A safety switch 107 connected to conductors 147 and 148is placed on the furnace for interrupting the circuit to the transformer90 in case of excessive pressures.

The operation of the apparatus is as follows. The primary of transformerV90 is normally continuously energized from the supply lines La and L4by means of conductor 146, and conductor 147, safety device 107 andconductor 148. As shown, thermostat 94 is the thermostat which controlsthe circuit. When the thermostat moves to the left hand contact callingfor heat a circuit is completed from the upper side of the low voltagesecondary of transformer 90, thermostat 94, conductor 144 the contacts112 and 113 on the time switch 62, conductor 71', bracket 139, thecontact 143, bridging member 81, contact 141, member 142, conductqr 145,starting coil 67, through conductor 105, the switch 104 which in itscold position is upon the right hand contact, conductor 104- to thelower side of the secondary of transformer 90. This energizes the coil67 which actsupon armature 68 to rotate the frame 68 about its pivots ina clockwise direction. This operation of the frame 68 meshes thepinion65 driven by the synchronous motor 61 and the gear 66 which results in acounter-clockwise rotation of the cam shaft carrying cams 63 and 64. Atthis movement of the frame the cams 63 and 64 are brought into contactwith the pivoted members 74 and 73 thus placing the members 74 and 73under the control of the cams as will be described in detail below. Theinsulating member 70 carried by arm 71 causes the member 711 to be movedabout its pivot in a clockwise direction closing the bridging member 126carried at its lower end on contacts 137 and 138. Closing of thesecontacts locks the coil 67 across the line thereby relieving thethermostat 94 of carrying the current which might damage the thermo-Astarting coil 67, from the other side of the starting coil throughconductor 105, right hand contact of the switch 104, conductor 104', tothe lower side of the transformer 90. The bridging member 691, carriedby arm 69 closes on contacts and 136 to complete the circuit fromconductor 92 to the pivoted member 74 to energize,

the ignition transformer as set forth below.

The detailed operation of the cams and pivoted switch members 73 and 74is as follows: As the frame 68 is moved by the coil 67 in a clockwisedirection the raised portion of cam 63 contacts with the curved upperend of pivoted member 74 and moves it in a clockwise direction againstthe bias of its spring 74. Upon further clockwise movement of the frameY68, the curved upper end of pivoted member 73 contacts with the bottomof a depression in the cam 64. From this point on both pivoted members73 and 74 move in a clockwise direction, the contacts 75 and 76 beingopen. When the gear 66 meshes with the gear 65, movement of frame 68 ina clockwise direction ceases and counterclockwise rotation of the cams63 and 64 begins.

As the camsrotate, the upper end of pivoted member 73 engages thebeginning of the iirst raised portion of the cam 64, and begins rotatingthe member 73 further in a clockwise direction. Just as the upper end ofmember 73 reaches the topI of the raised portion of cam 64 during thisclockwise movement of member 73, the upper end of member 74 drops intothe rst depression of the cam 63 rotating in a counterclockwisedirection closing contact 76 on 75 with a snap action. The member 73then acts as a stop member for the member 74. This closes the ignitionand the motor circuits.

The circuit through the fuel supply motor 100 may be traced from theline L3, conductor 146, conductor 101, motor 100, conductor 102, pivotedmember 74, contacts 76 and 75, pivoted member 73, conductor 131,conductor 147, safety device 107, conductor 148, to the other side ofthe line L1.

The circuit through the primary of the ignition transformer may betraced from line La, conductor 91, primary of transformer 91, conductor92, bracket and contact 135, bridging member 691, contact and bracket136, pivoted member 74, contacts 76 and 75, pivoted member 73, conductor131, conductor 147, safety device 107, conductor l48, back to the otherside of the 1`ne L4.

This causes the motor 100 to supply a fine spray of oil to the re box.At the same time an arc will be produced across the terminals 103connected to the secondary of transformer 91 by means of conductors 149and 150 for igniting the oil. When a ame is established the switch 104`due to the heat of the flame operates to close on the left handcontact. This results in the opening of the circuit through the startingcoil 67, permitting the frame 68 to pivot in a counterclockwisedirection to its normally opened position thus opening the ignitiontransformer circuit through bridging member 691. Before the circuitthrough coil 67 is broken, a circuit for energizing coil 72 is completedfrom the lower side of the secondary of transformer 90, through theconductor 104', switch 104, which momentarily bridges both contacts, theleft hand contact, conductor 106, to one side of the holding coil 72,from the other side of coil 72 to bracket 142, contact 141, bridgingmember 81, contact 143, bracket 139, contact 137, bridging member 126,contact 138, bracket 140, conductor to the upper side of secondary oftransformer 90. Coil 72 thus energized retains the pivoted member 711 inits attracted position. This keeps the bridging member 126 closed oncontacts 137 and 138 locking the coil 72 across the secondary oftransformer until the secondary of transformer 90 is shorted vbythermostat 94. The latch member 73 mounted on pivoted member 73 and incontact with the member 711, retains the pivoted members 73 and 74 in aposition to keep the contacts 75 and 76 closed, thus keeping the motorcircuit closed across the lines L3, L4. Thus until a change is calledfor by the thermostat, the fuel supply motor operates to supply a sprayof oil to the nre box of the furnace 60.

If the flame is not established while the ignition and motor circuitsare closed the frame will remain in operating position and the cams willcontinue to rotate since the cam shaft is in driving relation with thegear 65. As the cams rotate, the upper end of pivoted member 73 ridesalong the top part of the rst raised portion of cam 64, the contacts 75and 76 being maintained in the closed position. The beginning of the rstraised portion of cam 63 comes opposite the upper curved end of member74 just as the second depression on the cam 64 reaches the upper end ofmember 73. This permits the member 73 to drop into the second depressionand be rotated in a counter-clockwise direction by biasing spring 731.Pivoted member 74 is also rotated in a counterclockwise direction bymeans of its spring 74', the contacts 75 and 76 being maintained closed.However, when the upper end of pivoted member 74 contacts with the cam63, further counterclockwise movement of the member 74 is prevented andsince the member 73 continues to rotate in a counter-clockwise directionuntil the upper end of this member contacts with the bottom of thesecond depression on cam 64, contacts 75 and 76 open with a snap action.This opens the motor and ignition circuits.

The cams continue to rotate, the upper end of member 74 reaching the toppart of the first raised portion of cam 63 and riding along the same.The upper end of member 73 starts up the incline of the second raisedportion of cam 64 just as the upper end of member 74 drops into thesecond depression on cam 63 rotating in a counter-clockwise directionand again closing the contacts 76 and 75, thus reenergizing the motorand ignition circuits. If a flame is not established after apredetermined number of such operations, pin 78 mounted upon the gear 66will contact with the upper end of latch member 77 rotating this memberabout its pivot 77 in a clockwise direction to release lug 79 by movingthe recess 792 from the catch 79. This permits the spring 80 attached tothe pivoted frame member 80 which carries latch 77 to rotate the frame80 in a clockwise direction about its pivot 801 moving the bridgingmember 81 and away from contacts 141 and 143 and opening the circuitthrough the starting coil 67. The apparatus cannot again beset intooperation until the latch member 77 is manually reset.

By interchanging the conductors connected to pivoted members 73 and 74,the ignition transformer can be continuously energized during theintermittent operation of the motor. The circuit through the primary ofthe ignition transformer would then be from line La, conductor 91' toone side of ignition transformer 91, from the other side of ignitiontransformer 91, conductor 92, bracket and contact 135, bridging member691, contact and bracket 136, pivoted member 74, conductor 131,conductor 147, safety device 107, con-I ductor 148, to the other side ofthe line L4. Thus while frame 68 is in closed position placing thebridging member across contacts 135 and 136, the ignition transformerwill be continuously energized.

Should the fiame for any reason fail during operation of the furnace,the recycling mecha- 'nism as described above, will again be set intooperation to establish a flame when the switch 104 on cooling closes onthe right hand contact and makes a circuit through the conductor 105 toenergize coil 67. Due to the setting of the cams 63 and 64 a definitetime period elapses before the fuel supply motor and ignition system arere-energized as has been described above in detail, thus permittingaccumulated gases to be expelled from the furnace.

Upon failure of voltage after ame is established, the holding coil 72becomes deenergized. There is no force to then hold the pivoted member711 in its attracted position to maintain the bridging member 126 incontact with contacts 137 and 138. The latch 73 holding pivoted members73 and.74 with the contacts 75 and 76 closed, is released as the pivotedmember 711 rotates in a counter-clockwise direction to the openposition. Pivoted members 73 and 74 rotate in a counter-clockwisedirection opening the contacts 75 and 76 and return to their biasedpositions with the lugs 1271 and against the stop member 127 and pin130. Operation of the apparatus is again established when the voltagecomes back upon the lines and the recycling is again brought intooperation.

If suicient time has not elapsed for the switch 104 to return to itscool position due to only a momentary failure of voltage, if thethermostat 94 is still calling for heat, coil 72 will be reenergized andattract the pivoted member 711 to its closed position. This places thecoil 72 across the transformer and relieves the thermostat of the dutyof carrying current. Since the latch member 73 is in the raisedposition, the pivoted member 73 will not be operated to close contacts75 and 76 and hence the fuel supply motor will not be energized untilthe switch 104 returns to the cold position and the recycling apparatusis again set into operation.

With the ame established and a proper room temperature attained, thethermostat 94 will move to the right hand position. The closing of theright hand contact shorts the secondary of the transformer 90. Theshort-oircuiting circuit can be traced from the lower side oftransformer 90, right hand contact of thermostat 94, conductor 144,contacts 112 and 113, conductor 71', bracket 139, contact 137, bridgingmember 126, contact 138, bracket 140, conductor to the upper side of thetransformer 90. This deenergizes the holding coil 72 and permits thepivoted member 711 to return to its open position. Contacts 75 and 76are also moved tothe open position when the members 73 and 74 arerotated in a counter-clockwise direction against stops 130 and 127 bytheir biasing springs 731 and 74 deenergizing the motor 100. This isbecause member 711 and latch 73 are released from latching position whenstop pin 130 reengages lug 129' on latch 73. When the room temperaturehas cooled to the lower limit, the thermostat again operates to call theapparatus into operation to furnish more heat.

Mounted on top of the furnace 60 is a safety device 107 which may bethermostatically operated or operated by an excessive boiler pressure.This device normally closed, upon dangerous heat conditions, opens oneside of the circuit made by conductors 147 and 148 to the primary of thetransformer 90, thus deenergizing the holding coil 72 and shutting downthe apparatus. When normal conditions are again obtained the device 107closes and should the thermostat call for more heat the recyclingoperation again takes place.

The embodiment of the invention illustrated and described herein hasbeen selected for the purpose of clearly setting forth the purposeinvolved. It will be apparent h Wever, that the invention is susceptibleof being odified to meet the different conditions encountered in its useand I therefore aim to .cover by the appended claims all modificationsWithin the true spirit and scope of my invention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

l. In an oil burner control device, a driving means, a fuel supplymotor, circuit making and breaking means for controlling said fuelsupply motor, a cam shaft carrying circuit making and\ breaking\camscooperating therewith, movable means supporting said cam shaft,electroresponsive means for moving said last means to permit saiddriving means to rotate said cam shaft to energize said motor, a pivotedcircuit closing and opening member which is moved to the closed positionby said movable camshaft supporting means upon movement of said camshaft supporting means to driving position, latching means associatedWith said first circuit making and breaking means cooperating with saidmember to retain said first circuit-making and breaking means in circuitmaking position to maintain said motor energized under certainconditions, a second electro-responsive means for holding said member inthe closed position upon return of said cam supporting means to initialposition, and means for deenergizing said first electro responsive meansand energizing said second electro-responsive means under said certainconditions.

2. In a control for a heating device, electrically driven heating means,an electrical circuit therefor, circuit opening and closing means forcontrolling said circuit, a movable member carrying means adapted to,control said circuit opening and closing means, driving means for saidlast control means, electro-responsive means for moving said movablemember and control means carried thereby to control said circuit openingandclosing means for energizing said heating means, a secondelectro-responsive means, a movable armature therefor, and vlatchingmeans on' said circuit opening and closing means for cooperating withsaid armature to hold" said circuit opening and closing means in acircuit closing position to maintain said heating means energized whensaid first electro-responsive means is deenergized allowing said movablemember and control means to return to initial position, and thermostaticmeans for controlling operation of both of said electro-responsivemeans. y

3. In a control device for an oil burner, a fuel supply motor, circuitcontrolling members for controlling said fuel supply motor, a cam shaftv carrying cams adapted to cooperate therewith,

driving means for said camshaft, a movable member supporting said camshaft, a movable circuit opening and closing member biased to openposition, electro-responsive means for moving said cam shaft supportingmember to render said cam shaft operative, and means on said cam shaftsupporting member whereby movement of the same to operative positionwill move the movable circuit-opening and closing member for retainingsaid first members in circuit controlling position to maintain said fuelsupply motor energized when the cam shaft supporting member and camsreturn to initial position and said second electro-responsive means isenergized to hold said last member in circuit controlling position, andthermostatic means for controlling operation of both of saidelectro-responsive means.

4. In a control device for an oil burner, a fuel supply motor, anignition system, electrical circuits therefor, a plurality ofelectro-responsive means, pivoted circuit opening and closing means forcontrolling said circuits, one of said pivoted means being provided witha latch by means of which said pivoted means can be kept in circuitclosing position to maintain said fuel supply motor energized, a pivotedmember'actuated by one of said electro-responsive means supporting camsfor engaging with said pivoted circuit opening and closing means tocontrol the same, driving means for said cams, a second pivoted memberadjacent another of said electro-responsive means provided with a latchengaging portion, means on said first pivoted member to actuate saidsecond pivoted member upon energization of the electro-responsive meansactuating the rst pivoted member to cause said cams to engage saidcircuit opening and closing means, said latch and latch engaging portionof said second pivoted member cooperating to keep said circuit openingand closing means in a closed position When said secondelectro-responsive device is energized and said first electro-responsivemeans is deenergized to permit said first pivoted member to return toits initial position, and means for controlling energization of both ofsaid electro-responsive means.

5. In a control device for an oil burner, a fuel Supply motor, anignition system, electrical circuits therefor, a plurality ofelectro-responsive means, pivoted circuit opening and closing means forcontrolling said circuits, one of said pivoted means being provided witha latch by means of which said pivoted means can be kept in circuitclosing position to maintain said fuel supply motor energized, a pivotedmember actuated by one of said electro-responsive means supporting camsfor engaging with said; pivoted circuit opening and closing means tocontrol the same, driving means for said cams, a stationary pincooperating with said latch to retain said latch in a raised positionuntil said pivoted member is actuated by one of said electro-responsivemeans, a second pivoted member adjacent another of saidelectro-responsive means provided with a latch engaging portion, meanson said first pivoted member to actuate said second pivoted member uponenergization of the electro-responsive means actuating the first pivotedmember to cause said cams to engage said circuit opening and closingmeans, said latch and the latch engaging portion of said second pivotedmember cooperating to keep said circuit opening and closing means in aclosed position when said second electro-responsive device is energizedand said rst electro-responsive meansi's deenergized to permit saidfirst pivoted member to return to its initial position.

6. In a control device for an oil burner, a fuel supply motor, a circuittherefor, a pair of pivoted members having a cam engaging portion at oneend and carrying an electrical contact at thel other end, said contactscooperating with each other to open and close the circuit to energizesaid motor, said contacts being initially in the open' position,individual cams mounted adjacent the cam engaging portion of saidpivoted members and cooperating therewith to move said pivoted membersto open and close said contacts with a snap action, means for drivingsaid cams, said cams being formed to permit several operations of saidcontacts to intermittently energize said motor and means for thereafterrendering said cams ineffective whereby said contacts will remain in theopen position, and means permitting relative adjustment of said cams tovary the time said contacts remain in the open and closed positionsduring the above operation.

7. In an oil burner control means, a fuel supply motor, an ignitionsystem therefor, a plurality of cam actuated circuit controlling membersfor controlling said motor and ignition system, cams mounted on amovable shaft and adapted to intermittently actuate said circuitcontrolling members, driving means for said cams, said cams beingrelatively adjustable to permit the periods said circuit controllingmembers-are opened and closed to be varied, electro-responsive means tomove said shaft and cams to an operating position to actuate saidcircuit controlling members to energize said motor and ignition systemfor initiating combustion, a second electro-responsive device operativeonly after heating conditions are established and means cooperatingtherewith and with said circuit controlling members for maintaining saidfuel supply motorv energized to maintain combustion, a means responsiveto said combustion for deenergizing said first electro-responsive meansto permit said camshaft and cams to return to initial position and toenergize said second electro-responsive means to maintain combustion andthermostatic means for deenergizing said second electro-responsive meanswhen a suffcient amount of heat is furnished.

8. In an oil burner control, a fuel supply motor and ignition systemtherefor, a pair of cooperating cam actuated circuit controlling membersfor intermittently energizing said motor and ignition system, camsrelatively adjustable to vary theI peri-ods said circuit controllingmembers are in the open and closed position, means adapted to drive saidcams, an electro-responsive means controlling operation of said cams bysaiddriving means to cause intermittent operation of said fuel supplymotor to initiate heating conditions, a second electro-responsive meanshaving latching mechanism cooperating with one of said cam actuatedcircuit controlling members to maintain said fuel supply motor energizedafter heating conditions have been established, heat responsive meansoperatively associated with both of said electro-responsive means forpreventing energization of said electro-responsive initiating meansafter a combustion failure until initial conditions are obtained, andthermostatic means menacer than a sufficient amount of heat is furnishedto maintain heating conditions.

9. In a heat control apparatus, an electrically operated fuel projectingmeans, circuit making and breaking devices for controlling the fuelprojecting means, electrically operated means for intermittentlyactuating said devices, a trip mechanism provided with a circuit openingand closing member for controlling said electrically operated fuelprojecting means, means actuated by said intermittent actuating means toactuate said trip mechanism after a predetermined number of intermittentoperations' to render said actuating means ineffective to actuate saidcircuit making and breaking devices, and means on said trip mechanismfor manually operating said trip mechanism to deenergize saidelectrically operated fuel projecting means after it has been onceenergized and for resetting said trip mechanism to permit said fuelprojecting means to be again intermittently operated.

l0. A control for a burner, including electrically driven fuelprojecting means, circuit-making and breaking means for controlling saidfuel projecting means, an electrically driven cam mechanism forintermittently operating said circuit-making and breakingY means toenergize said fuel projecting means, and a trip switch mechanism`operated by said electrically driven cam mechanism to render said cammechanism ineffective after a predetermined number of intermittentoperations.'

11. A control apparatus for a burner, including electrically driven fuelprojecting means, circuitmaking and breaking means for controllingenergization of said fuel projecting means, electrically driven cammechanism for operating said circuit-making and breaking means, and atrip mechanism provided with a circuit-making and breaking memberactuated by said cam mechanism after a predetermined number ofintermittent operations to render said cam mechanism ineifective.

12. A control device for a burner having an y electrically driven fuelprojecting motor, including circuit controlling mechanism for saidmotor, electro-responsive means for operating said circuit controllingmechanism to intermittently energize said fuel projecting motor toinitiate combustion, a second electro-responsive means associated withsaid circuit controlling mechanism for maintaining said fuel projectingmotor energized when combustion is established, means responsive tocombustion for deenergizing said second electro-responsive means andthereafter energizing said first electro-responsive means in response tofailure of combustion and athermostat for causing energization of saidrst electro-responsive means to initiate combuston and for causingdeenergization of said second electro-responsive means to stop operationof said fuel supply motor when sufficient heat has been' furnished.

13. A control apparatus for a burner having an electrically driven fuelprojecting means including an electro-responsive cam-operatedcircuit-making and breaking mechanism for intermittently energizing saidfuel supply means to establish combustion, a second electro-responsivemechanism operably associated with said circuit-making and breakingmechanism and adapted to maintain said fuel projecting means energizedafter combustion is established, and a double circuit thermostatic meansfor deenergizing said second electro-responsive mechanism and energizingsaid first electro-responsive mechanism when combustion fails.

14. A combustion heating device having in combination, an electricallydriven fuel projecting means; electrically driven cam-operatedintermittent circuit-making and breaking mechanism adapted to controlsaid fuel-projecting means, an electro-responsive device for renderingsaid circuit-making and breaking mechanism operative to intermittentlyenergize said fuel projecting means to establish combustion, a secondelectroresponsive device operatively associated with said circuit-makingand breaking mechanism to maintain said electrically driven fuelprojecting means energized independently of the first electro-responsivedevice after combustion is established, and means responsive tocombustion for deenergizing said second electro-responsive device andenergizing said first electro-responsive device when combustion fails.

15. A control device for a burner having an electrically driven fuelprojecting means, including circuit controlling mechanism therefor,electro-responsive means associated with said circuit controllingmechanism for energizing said electrically driven fuel projecting meansto initiate combustion, a second electro-responsive means associatedwith said circuit controlling mechanism for maintaining saidelectrically driven fuel projecting means energized, a transformeroperatively associated with both of said electro-responsive means, athermostat in the secondary of said transformer for causing energizationof said first electro-responsive means to initiate combustion, and meansfor deenergizing said second electroresponsive means and energizing saidfirst electro-responsive means when combustion fails, said thermostatshortcircuiting the secondary of said transformer when sufficient heathas been furnished for deenergizing said second electro-responsive meansto stop operation of said electrically driven fuel projecting means.

16. A control device for a burner having an electrically drivenfuel'projecting means, including circuit-controlling means therefor, atransformer having a low-voltage secondary, an electro-responsive deviceoperatively associated with said circuit-controlling means andcooperating therewith to initiate combustion and adapted to be energizedfrom said low-voltage secondary, a second electro-responsive deviceadapted to be energized from the secondary of said transformer andassociated with said circuit-controlling means for maintaining saidelectrically driven fuel projecting means energized, a thermostatassociated with said transformer for establishing a circuit through saidfirst electro-responsive device to initiate combustion, a deviceresponsive to the combustion conditions for causing deenergization ofsaid second electro-responsive device and for causing energization ofsaid first electro-responsive device When lcombustion* fails, saidthermostat short-circuiting the secondary of said transformer to causedeenergization of said second A electro-responsive device to stopoperation of said said fuel supply motor and ignition system to initiatecombustion, electro-responsive means operatively associated with saidcircuit controlling mechanism for rendering said circuit controllingmechanism operative to initiate combustion, a second electro-responsivemeans operably associated with said circuit controlling mechanism formaintaining said fuel supply motor energized when combustion isestablished, means responsive to combustion conditions for deenergizingsaid second electro-responsive means to cause deenergization of saidfuel supply motor and for re`- energizing said rst electro-responsivemeans to reenergize said fuel supply motor when combustion fails, meansfor maintaining said ignition system deenergized after fiame failureuntil said combustion responsive means reenergizes said firstelectro-responsive device to operate said intermittent circuitcontrolling mechanism, and a master control thermostat for energizingsaid first electro-responsive means to initiate combustion and todeenergize said second electro-responsive means to stop operation ofsaid motor when sufiicient heat has been furnished.

18. In a combustion heating device, electrically driven combustionheating means, an energizing circuit therefor having relatively movablecontacts therein biased to open the circuit, cam means forintermittently closing said contacts, electroresponsive means forrendering said cam means effective to close said contacts intermittentlyto energize said heating means, and a second electroresponsive meansdependent upon energization of said first electroresponsive means forholding said contacts closed against their bias, and switching meanscontrolled in accordance with combustion conditions for deenergizingsaid first electroresponsive means to render said cam means ineffectiveand for maintaining said second electroresponsive means energized tomaintain said electrically driven combustion heating means energized.

19. In a heat control apparatus, the combination of an electric motordriven fuel feeding means, switch mechanism for intermittentlyenergizing said means, electroresponsive means for controlling theoperation of said mechanism, latch mechanism provided with a circuitcontrolling member connected to control the energization of saidelectroresponsive means, and means actuated by said intermittent switchmechanism for tripping said latch mechanism after a predetermined numberof successive intermittent operations to deenergize said electricallyoperated means.

20. in a combustion heating device the combination of an electricallydriven fuel feeding means, circuit controlling means therefor, means forintermittently operating said circuit controlling means,electroresponsive means for rendering said intermittent operating meansoperative to initiate combustion, a second electroresponsive means formaintaining said electrically driven fuel feeding means energized aftercombustion is established, and switching means responsive to combustionfor preventing energization of said first electroresponsive means untilafter deenergization of said second electroresponsive means upon failureof combustion.

21. A control for a burner having a fuel feeding motor and an ignitionsystem therefor including circuit controlling means for energizing saidmotor and ignition system. a first electroresponsive means operativelyassociated with said circuit controlling means for rendering said meansoperative to initiate combustion, a second electroresponsive meansrendered operative upon operation of said first electroresponsive meansand operatively associated with said circuit controlling means formaintaining said fuel feeding motor energized when combustion isestablished, switching means responsive to combustion conditions fordeenergizing said second electroresponsive means and for reenergizingsaid rst electroresponsive means when combustion fails, the said secondelectroresponsive means being responsive to voltage failure formaintaining said ignition system and fuel supply motor deenergized untilsaid combustion responsive means reenergizes said iirstelectroresponsive means.

22. An oil burner control device including, an electrically operated oilburner, a circuit making and breaking device for intermittentlyenergizing said burner, an electric timing means therefor, an ignitionsystem for said burner, a movable frame carrying a cam shaft movablethrough a series of positions in timed sequence for intermittentlyactuating said circuit making and breaking device and a contact forclosing a circuit to said timing means and said ignition system,electroresponsive means for moving said frame to an operative positionto initiate heating conditions, a heat responsive circuit controllingdevice in series with said contact for deenergizing said ignition systemand said timing means with said cam shaft in one of said positions tomaintain heating conditions upon establishing heating conditions, and atripping device for deenergizing said electroresponsive means if no ameis estabmessbar means and said ignition system, electroresponsive meansfor moving .said frame to an operative position to initiate heatingconditions, a thermostat for energizing said electroresponsive means, asecond member on said frame for short circuiting said thermostat whensaid frame moves to said operative position, a heat responsive circuitcontrolling device in series With said timing motor and ignition systemcircuit controlling member for deenergizing said ignition system andsaid timing means with said circuit making and breaking device inenergizing position to maintain heating conditions upon establishingheating conditions, and a tripping device for deenergizing saidyelectroresponsive means if no flame is established after apredetermined number of intermittent operations.

GEORGE R. TOWNSEND.

